Definition of escape velocity in English:

noun

What would happen if the escape velocity of a planet were greater than the speed of light?

The work presented in these two papers formed the basis for a later study of black holes, showing that bodies of sufficiently large mass would have an escape velocity exceeding the speed of light and so could not be seen.

If the object slows down below a minimum orbital velocity, it will hit the planet; if it speeds up beyond a maximum escape velocity, it will move away from the planet permanently.